Python list of dictionaries containing lists comprehension

I have a list of dictionary containing lists:

a = [{'alpha':'a','val':10,'num':['one','two']},{'alpha':'b','val':22,'num':['two']},{'alpha':'c','val':1,'num':['seven']},{'alpha':'a','val':10,'num':['three','nine']},{'alpha':'b','val':9,'num':['two','four']}]